Lifting pull gear engaging hoist



May 11, 1954 A. v. JENSEN LIFTING PULL GEAR ENGAGING HoIsT Filed June 27, 1951 Patented May 11, 1954 UNITED sTATEs PATENT OFFICE LIFTING PULL GEAR ENGAGING HOIST Adolph V. Jensen, Council Bluffs, Iowa Application June 27, 1951, Serial No. 233,835

. to permit the quick adjustment of the exible connector length prior to lifting. The relative movement of the gear to release them is in a direction such that when lifting force is applied the `gears are automatically brought into engagement again.

The principal object of my invention is to provide a lifting pull gear engaging hoist the flexible lifting element of which is quickly adjusted to the correct length and thereafter quickly placed in condition to commence lifting opera tions by applying lifting force.

It is a further object of my invention to provide a lifting pull gear engaging hoist the gears of which are held in meshing relation with each other by a force that varies directly with the amount of the load being lifted. l

It is a further object of my invention to provide a lifting pull gear engaging hoist that is extremely compact to make it easy to carry about and capable of the maximum lift in relation to a determined point of support.

A still further object of my invention is to provide Aa lifting pull gearengaging hoist that is of simple construction thus making it economical to manufacture and use.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangement, and combination of the various parts of thedevice, whereby the objects contemplated are attained as hereinafter more fully set forth, pointed out in my claim, and illustrated in the accompanying drawings, in which:

Fig. 1 is a perspective view of my lifting pull gear engaging hoist with dotted lines showing the adjusting use of the crank handle,

Fig. 2 is a cross-sectional view of my device taken on the line 2-2 of Fig. 1,

Fig. 3 is a side elevation View of my device with a concealed part shown with broken lines, and

Fig. 4 is a longitudinal sectional view of my device taken on the line 4-4 of Fig. 2.

Referring to the drawings, I have used the numeral I to designate themain frame of the` hoist. I have shown it for purposes of illustration as being a single piece of sheet metal formed into a rectangular element open at both ends.

The free ends of the sheet are joined in some` appropriate manner as by the screws I I. A worm I2 is rigidly secured to a shaft I3, or formed integrally therewith, that is appropriately journaled in a pair of spaced apart bearings I4. These bearings are rigidly secured to frame I0 in any suitable manner as by the screws I5 or the like. Each end of shaft I3 has a squared portion I6 that :lits a similarly shaped well in crank handle Il.

A worm gear designated I8 is used to form` one side of a drum It on which the cable 20 or other flexible lifting connector element is wound during lifting operations and for storage. 4'Ihe cable is prevented from slipping oif the other side of drum I9 by side plate 2l. The outside ends of the drum and worm gear mechanism form a bearing end 22 and an adjusting drive 23. All these parts that revolve with the drum are here shown as formed integrally but that is not essential to my invention. The only necessary feature is that the adjusting drive, the drum and the worm gear be rigidly secured together so `that torque applied to one is equally applied to `for hinged movement in relation to frame I0 by a pair of like pivots designated 25 only one of which is shown in Figs. 1, 3 and 4. A lever member 26 is rigidly secured to or formed integrally with the channel member 2li and extends upwardly through an appropriate slot 21 made in frame I0. The openings in the sides of frame I0 through which the bearing end 22 and adjusting drive 23 extend are elongated ovals as shown in Figs. 1 and 2. The purpose of these elongated openings is to permit the hinging movement of channel member 24 as shown in Fig. 4.

A guide stop member 28 may be rigidly secured to frame I0 if desired, but the guide is not essential to the invention. A means for securing the hoist to a fixed support or the item to be lifted must be provided. A simple and convenient means is eye 29 that is secured to frame III by nut 30. A hook or some other appropriate fastening means should be provided at the end of the flexible element, and such means is here shown illustratively as the grommet 3| inserted in the cable loop 32 that is secured by band 33. This completes the description of my device and I will now explain its operation and use.

To use my hoist a suitable support properly located relative to the object to be lifted is dis- 4siderable safety factor. vof the gear and Worm becoming .unmeshecl and covered. To'this support either eye 29 or cable loop 32 is secured. The lever 26 is then moved to the position illustrated in Fig. 4 and the gear I8 is released from worm I2 so that it will free wheel. If it is more convenient to do so, these rst two steps may be reversed. When the gear I8 is free to rotate, the cable 20 is easily paid out until the hoist can be connected to the object to be lifted. The crank I1 is then placed on the adjusting drive 23 as suggested by the dotted lines in Fig. 1. Since the slack in the cable is the only load applied to drum I9 at this point the direct drive connection of the crank handle is suflicient leverage and is of course much faster than the geared drive. As the weight ofthe object to be lifted is applied to the device when all slack has been taken up, the furtherturning of adjusting drive 23 by crank handle Il' causes a pressure to be exerted on drum I9 that causes it and form gear I8 with it to be slidably moved toward and into meshing relation with Worm I2..

Atthis point it is no longer possible to rotate ad'- V.iusting drive 23 with the crank. The crank is thereafter placed on either of squared ends I6 Y of shaft I3 and the lifting process carried out by rotating Worm I2; The Worm and VWorm gear arrangement Will hold any given adjustment. To lower an object, crank handle I1 is rotated in a reverse direction.

Since the Wormand Worm gear are held in contactvvth each other in proportion to the amount of tension exerted on the cable, it is not possible to unmeshthe gear and the worm to lower a lifted load. However, once the load is lowered, and the hoist is to be prepared for storage; itis possible to free Wheel the drum. This permits crank handle I1 to be placedy on adjusting drive 23 to reel up the cable rapidly.

This hoist is very compact and .easily transportedV when itis reeled up. Also the mechanism is practically fool proof.VV It is also clear from the foregoing how quickly and easily theVY hoist is adjusted and prepared for lifting. The fact that the pull'V eierted during lifting actions holds the tion and arrangement of my lifting pull gear engaging hoist without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claim, any modif-led forms of structure or use. of mechanical equivalents which may be reasonably included Within their scope. Y Y

I claim:

Y In a lifting device; an open end Arectangular frame having a `slot opening` in its top; a pair of vertically extending centrally arranged slots, one in each side of said frame in alignment with each other; a channel-shaped member pivotally mounted inside said frame and pivoting on an axis eccentric to the slots in said frame sides;

said channelesliaped member having holes there- Y in that alignwith., the slots in said frame sides;

a drum and Worm gear assembly rotatably v mountedVA in said channel-shaped member holes gear and the worm toward each other is a con- There is nol possibility dropping a" lifted load suddenly' to the possible injury of equipment and personnel.

vSome changes maybe made ln thel construeand having portions thereof extending intovsaid slots; a worm rotatably mounted in said yframe below said drum and Worm gear assemblyi a .exible element wound on said drum; a Vlever secured to said channel-shaped member and ex- .tending throughV the opening in said rectangular frame and beyond said frame for pivoting said channel-shaped member; at least one drive secured to said worm; a drive secured to said drum Vand worm gear assembly and accessible from the outside of said frame; and a crank handle selectively engageable with said drive; lsaid Vvvvorm and Worm gear being in' mesh V-When said` channel# shaped member is pivdted to 'carry said drum'l and worm gear assembly to a' relatively -lowpositin on said frame and disengaged When' saidv channel'-V shaped member is pivoted to carry saidfdrum `and worm gear assembly to a"relatively h'ighfpo'sition Y on said frame.

eferencesoitee in the meer this patent UNITED STATES PsirNrsj Numberj Name 1 Date fil-1,165V YNoackv a .Y Sept. 17,1389 756A@ 'Asiwp 1- Apr. 5. 190.4 Jensen Q y Y. regeren Parleurs. `1 .Number j Cheney Y Datel 

